Optical absorption of single-layer hexagonal boron nitride in the ultraviolet

Henriques, J. C. G.; Ventura, G. B.; Fernandes, Carlos Diogo Monteiro; Peres, N. M. R.

doi:10.1088/1361-648x/ab47b3

Cited by 41 publications

(46 citation statements)

References 47 publications

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“…8b, which depicts the changes both in the optical ΔE opt = E 0 (ε m ) − E 0 (ε m = 1) and QP ΔE QP ¼ Σ xc 0;þ ðε m Þ À Σ xc 0;þ ðε m ¼ 1Þ gaps. Here, E 0 is the ground-state exciton energy, and Σ xc 0;þ accounts for the exchange-correlation function 191 . More details are presented in the Supplemental Material.…”

Section: Dielectric Screening and Many-body Effectsmentioning

confidence: 99%

Bandgap engineering of two-dimensional semiconductor materials

et al. 2020

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Semiconductors are the basis of many vital technologies such as electronics, computing, communications, optoelectronics, and sensing. Modern semiconductor technology can trace its origins to the invention of the point contact transistor in 1947. This demonstration paved the way for the development of discrete and integrated semiconductor devices and circuits that has helped to build a modern society where semiconductors are ubiquitous components of everyday life. A key property that determines the semiconductor electrical and optical properties is the bandgap. Beyond graphene, recently discovered two-dimensional (2D) materials possess semiconducting bandgaps ranging from the terahertz and mid-infrared in bilayer graphene and black phosphorus, visible in transition metal dichalcogenides, to the ultraviolet in hexagonal boron nitride. In particular, these 2D materials were demonstrated to exhibit highly tunable bandgaps, achieved via the control of layers number, heterostructuring, strain engineering, chemical doping, alloying, intercalation, substrate engineering, as well as an external electric field. We provide a review of the basic physical principles of these various techniques on the engineering of quasi-particle and optical bandgaps, their bandgap tunability, potentials and limitations in practical realization in future 2D device technologies.

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Section: Dielectric Screening and Many-body Effectsmentioning

confidence: 99%

Bandgap engineering of two-dimensional semiconductor materials

et al. 2020

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“…In this work, and contrary to Ref. [23], we opt to work with a Slater basis instead of a Gaussian one since this choice allows us to obtain more accurate results using fewer terms in Eq. (7).…”

Section: Model Hamiltonianmentioning

confidence: 99%

Excitons in phosphorene: A semi-analytical perturbative approach

Henriques

Peres

2020

Phys. Rev. B

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In this paper we develop a semi-analytical perturbation-theory approach to the calculation of the energy levels (binding energies) and wave functions of excitons in phosphorene. Our method gives both the exciton wave function in real and reciprocal spaces with the same ease. This latter aspect is important for the calculation of the nonlinear optical properties of phosphorene. We find that our results are in agreement with calculations based both on the Bethe-Salpeter equation and on Monte Carlo simulations, which are computationally much more demanding. Our approach thus introduces a simple, viable, and accurate method to address the problem of excitons in anisotropic two-dimensional materials.

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“…Further, small differences in the values of absorption coefficient do not significantly affect the overall estimation of the κ and g. Hence, our assumption is reasonably acceptable.) [9,[12][13][14] ( ) W m -2 = 34.630 × 10 7 W m -2…”

Section: S10mentioning

confidence: 99%

“…To note that small differences in the values of absorption coefficient do not significantly affect the overall estimation of the κ and g. Hence, our assumption is reasonably acceptable. )[9,[12][13][14] ( ) W m -2 = 18.550 × 10 7 W m-2 Similarly, for 20× the peak absorbed laser power per unit area (q2 ): where, = Total absorbed laser power = Laser spot radius for 20× objective S11 = Optical absorption coefficient = 0.038 ( ) W m -2 = 15.019 × 10 7 W m -2 Thickness ( ) of the BG heterostructure = (3.4+0.335) nm = 3.735 nm (It is approximately considered as the sum of the 11 layers: one monolayer of graphene and 10 layers of h-BN).…”

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confidence: 99%

Hexagonal Boron Nitride–Graphene Heterostructures with Enhanced Interfacial Thermal Conductance for Thermal Management Applications

Karak

Paul

Negi

et al. 2021

ACS Appl. Nano Mater.

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Atomically thin monolayers of graphene show excellent electronic properties which have led to a great deal of research on their use in nanoscale devices. However, heat management of such nanoscale devices is essential in order to improve their performance. Graphene supported on hexagonal boron nitride (h-BN) substrate has been reported to show enhanced (opto)electronic and thermal properties as compared to extensively used SiO 2 /Si supported graphene. Motivated by this, we have performed temperature-and power-dependent Raman Spectroscopic measurements on four different types of (hetero)structures: (a) h-BN (BN), (b) graphene (Gr), (c) h-BN on graphene (BG), and (d) graphene encapsulated by h-BN layers from both top and bottom (BGB), all supported on SiO 2 /Si substrate. We have estimated the values of thermal conductivity (κ) and interfacial thermal conductance per unit area (g) of these four (hetero)structures to demonstrate the structure-activity (thermal) relationship. We report here the values of κ and g for h-BN supported on SiO 2 /Si as 280.0±58.0 Wm -1 K -1 and 25.6±0.4 MWm -2 K -1 , respectively. More importantly, we have observed an improvement in both thermal conductivity and interfacial thermal conductance per unit area in the heterostructures which ensures a better heat dissipation in devices. The κ and g of h-BN encapsulated graphene on SiO 2 /Si (BGB) sample was observed to be 850.0±81.0 Wm -1 K -1 and 105±1 MWm -2 K -1 , respectively, as opposed to 600.0±93.0 Wm -1 K -1 and 1.15±0.40 MWm -2 K -1 , respectively, for graphene on SiO 2 /Si substrate. Therefore, we propose that for graphene-based nanoscale devices, encapsulation with h-BN is a better alternative to address heat management issues.

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Optical absorption of single-layer hexagonal boron nitride in the ultraviolet

Cited by 41 publications

References 47 publications

Bandgap engineering of two-dimensional semiconductor materials

Bandgap engineering of two-dimensional semiconductor materials

Excitons in phosphorene: A semi-analytical perturbative approach

Hexagonal Boron Nitride–Graphene Heterostructures with Enhanced Interfacial Thermal Conductance for Thermal Management Applications

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